Abrading apparatus



Feb. 15, 1944. w EE 2,341,560-

ABRADING APPARATUS Filed Sept. 11, 1942 3 Sheets-Sheet awe/whom Feb. 15, 1944. w. L. KEEFER- ABRADING APPARATUS Filed se it, 11, 1942 3 Sheets-Sheet 2 3162212 fizefer I w. KEEFER AB RADING AEPARATUS Feb. 15,1944.

5 sheets-sneak} Filed Sept. 11, 1942 Patented Feb. 1944' NlED STATES PATENT 2,341,560 ABRADHNG APPARATUS Walter L. Keefer, Hagerstown, MIL, assigns: to

Pangborn flcrporation, Hagerstown, Md, a corporation of Maryland Application September 11,1942, Serial No. 457,982 7 13 @Claims.

The present invention relates to abrading ap= paratus of the type for centrifugally propelling or throwing relatively small particles at abrading or blasting velocities. The invention more specifically pertains to means for transferring the abrasive particles f om a supply source to a predetermined position or zone within the path de-" the provision of means having a minimum number of relatively movable parts for efilciently feeding the abrasive particles'to the propeller blades. of the rotor wherein the feeding means or means for transferring the abrasive to the-rotor is mounted in such a manner as to be readily accessible for maintenance and adjustment.

Another object of the invention resides in providing an abrasive transfer mechanism which may be readily adjusted to supply abrasive particles at any circumferential point or zone permitting the abrasive to be discharged from-the rotor at any zone of limited arcuate extent thereby providing abrading or blasting apparatus for universal application.

A still further'object-of the invention resides in providing an abrasive transfer mechanism wherein the abrasive is dispersed or spread as it is supplied to the propeller blades thereby reducing the tendency of the abrasive to wear channels in the propeller blades.

A more specific object of the invention resides in providing a rotating cup between the inner ends of the propeller blades having a circumferential slot extending therearound through which theabrasive particles may be discharged as a result of the centrifugal force developed during rotation of the cup including means for normally closing or obstructing the slot at all circumferential points of the cup and means for deflecting the closure means to open the slot atone point in'the rotation of the cup.

Other objects and features of the invention will be more apparent as the present disclosure 1 proceeds and upon consideration of the following .....deta iled description and the appended drawings wherein an exemplary embodiment of the invention is disclosed.

In the drawings:

Fig. 1 is an axial sectional view of abrading apparatus embodying the invention.

Fig. 2 is a sectional view of the transfer mechanism taken on the line 2-4 of Fig. 1 and showing a portion of the rotor in elevation.

Fig. 3 is an exploded sectional view of the V hollow annular members which form the cup assembly and the closure ring member of the transfer mechanism. Fig. 4 is an end elevational'view of the apparatus illustrating a portion of the housing .with

the feed spout removed.

Referring to the drawings, and particularly to Fig. 1, there is shown at R a rotor which includes a disc or rimner head l2 suitably secured to and rotatable with a driving shaft l4 and a plurality of propeller blades l6 removably secured to the disc or runner head I! in any conventional manner. The propeller blades may be mounted on the disc l2 by means of dovetailed edges l8 provided on the propellerblades l6 which are arranged in substantially radially extending dovetailedgrooves 22 provided in or on the disc or runner head II. The propeller blades l6 may be securely maintained in operative positions on the runner head or disc I! against radial outward movement by any suitable means (not shown). Each of the propeller blades is provided with a flange 24 along the outer or free edge thereof and on the forward face of each blade It for the purpose of preventing the abrasive particles from spilling over the outer or free edges of the propeller blades. The propeller blades l6 extend inwardlyshort of the axis of the rotor and preferably terminate at a considerable distance from the axis to permit a transfer mechanism T to be mounted at the central portion of the rotor between the inner ends of the propeller blades. The propeller blades l6 are preferably beveled or sharpened at their inner ends 26 so as to more eificiently intercept the abrasive discharged by the transfer mechanism.

A primary feature of the invention pertain to the mechanism T for transferring abrasive particles from a supply source to a position to be engaged by the propeller blades l6 at one point or zone in the rotation thereof. In carrying out the invention the apparatus is so designed and arranged that abrasive is discharged from the transfer mechanism entirely by means of centrifugal force acting thereon and for thi purpose the transfer mechanism'T is rotatable and nular slot around the periphery of any type of rotating cup and the annular members 34 and 36 provide one exemplary arrangement for the formation of such a peripheral opening. Thus the annular members 34 and 36 may be spaced from each' other at the peripheries thereof to pro-' vide an annular slot 38 as shown in Fig. 1 extending circumferentially'around the cup' assembly. The hollow annular member 36 is preferably provided with a cylindrical flange portion 42 which is "adapted to be seated in a central opening in the disc or rimner head l2. The hollow annular member 34 may for example be secured in an operative position and properly supported and spaced from the hollow annular member 36 to provide the annular slot 38 by means of aplurality of internally arranged arms 44 which extend within the annular member 36. The annular member 34 includes a radial wall 52 formed integral with the circumferentially spaced arms 44. The wall 52 may be provided with a cylindrical flange 46 adapted to fit snugly within the inner end of the annular member 36 as shown in Fig. 1 and engage a lip 41 on the annular member 36. Such an arrangement provides the advantage that both of the hollow annular members 34 and 36 may be properly secured to the rotor R so as to rotate therewith by mean of a bolt 48 extending through an opening in the radial wall 52.into threaded engagement with the hub portion 54 of the rotor. Thus when the bolt 48 is threaded into the hub and the bolt moves towards the right in Fig. l the flange 46 will engage the lip 41 and rigidly maintain the cup assembly on the rotor. These parts of the cup are so shaped and arranged as to position the annular slot 38 in a plane substantially medially of the propeller blades l6.

The invention includes means for closing or obstructing the annular slot 36 of the transfer mechanism T at all but one annular point thereof during operation, and such closure means may take the form of a flexible elastic ring member 56 of proper cross section adapted to be normally seated on the inner annular edges of the cup assembly adiacent the slot 38 and these parts of theannular members 34 and 36 are preferably shaped as valve seats 68 and 62. The ring member 56 may for example be formed of rubber or any suitable flexible and elastic material such as synthetic materials or artificial resins. The ring member should be of a diameter substantially equal to the diameter of the valve seats 58 and 62 to thereby normally engage the cup assembly whereby the ring member. is rotated with the annular members 34 and 36. The ring mem-- ber 66 is preferably so formed as to have sig-" niflcant mass so that during rotation of the cup assembly and the ring member 56 centrifugal force acting on the ring will tend to urge the ring member radially outward at all circumferential points to obstruct or close the circumferentially extending slot 36 and the elastic characteristics thereof facilitate closure of the periphery of the cup. In assembling the cup the elastic ring member 66 is first arranged over the arms 44. The arms 44 are each provided with a groove 63 .ber 34. The abrasive supplied to the feed spout may thus pass into the cup of the transfer mechanism T. The abrasive moving into the cup follows a course indicated approximately by the arrows shown in Fig. 1. Thus the abrasive moves towardsthe inner wall or walls of the-cup assem bly and upon engagement thereof the abrasivequickly attains the same speed as that of the elastic ring 56 and the cup proper, thereby reducing to a minimum any abrasion of the ring member 56 and the annular members 34 and 36. The arms 44 supporting the hollow annular member 34 also serve to engage and move the abrasive circumferentially as it enters the cup and thus assists in accelerating the abrasive to the rotating speed of the transfer mechanism. The abrasive thus builds up on the wall or walls of the cup as a result of the centrifugal force acting on the abrasive within the cup during rotation thereof. Some of the abrasive rests' on the ring member 56 to more effectively urge the ring membeer to the slot closing position.

The invention also includes means for distributing the abrasive to each side of the ring memher 56 and such means may take the form of an annular partition 66 mounted within the cup and of frusto-conical shape sloping towards the inner end of the feed spent as shown in Fig. 1. The partition 66 also serves to reinforce the arms 44 and may be formed integral therewith. The inner edges of thearms 44 may also be beveled as shown at 12 in Fig. 2 to more efllciently intercept the abrasive entering the cup from the feed spout 32. Thus the abrasive is more positively supplied to each side of the ring member 56 by the partition 66 and when the slot'38 is opened as hereinafter described the abrasive leaves the cup from both sides of the ring member 56 to disperse the abrasive over a relative wide area of the propeller blades 16 and thereby prevent the abrasion of a relatively narrow channel in each of the propelling faces thereof.

While the inner walls of the annular members 34 and 36 may be of any shape, the invention includes the feature of arranging these walls to slope outwardly towards the peripheral slot 38. Thus, the inner walls 14 and 16 are frusto-conical shaped and converge outwardly toward each other and towards the annular slot 38 as shown in Fig. 1 whereby the abrasive particles may move outwardly on these frusto-conical inner wall surfaces at both sides of the ring member 5.6 to positions for being readily discharged through the slot 38 when the ring member 56 is deflected from the closed position in a manner as hereinafter described.

The outer or free end of the rotor' is preferably enclosed so as to prevent splattering or unobstructed movement of free abrasive particles which have improperly engaged the propeller blades IS. The closure means may take the form of a housing partly illustrated at H in Figs. 1 and 4 provided ,with replaceable wear plate or plates "18 as shown in Fig. 1. The housing H and the .mounted. The feed spout holder 84 may be maintained in an operativeposition by any suitable means such as a plurality of clamps 88 which may be loosened to permit circumferential adjustment of the disc member 84. The feed spout holder or disc member 84 is also provided with a central opening 88 for permitting the feed spout 32 to extend therethrough and an adjacent portion of the feed spout may be provided with an annular flange 92 for attachment tothe feed spout holder 84.

The invention embraces relatively stationary cam means for deflecting or moving the flexible ring member 58 from a position closing the slot 38 at one point in the rotation of the cup assembly. Such cam means may be provided by a roller or disc 94 mounted to frictionally engage the ring member 58 and flex or move the ring member 58 radially inward at one point in the rotation thereof as shown in Fig. 2. The disc or roller 34 may therefore be provided with an arcuate groove 98 in the periphery for frictionally engaging the periphery of the ring 58 so that the disc or roller 94 is driven by the rotating ring member 58. Thedisc or roller 94 may be rotatably mounted in any fixed position in any suitable manner such as by means of a shaft 98 rotating in bearings I82.

The bearings I82 are preferably encased in a small cylindrical housing I84 which may be mounted in an aperture provided in the disc member 84 as shown in Fig. l. The disc or roller 94 may also be provided with a depending annular flange I88 for preventing abrasive from entering the casing I84 to destroy the bearings I82. The disc or roller assembly maybe retained in an operative position in the aperture of the disc member 84 by any suitable means such as a set screwI88. The circumferential position at which the disc or roller 94 engages the ring member 58 may be. adjusted by rotating the disc member 84.

' Such adjustment of the position of the roller 94 of the propeller blades points except where the ring member 58 is flexed inwardly by the roller or disc 84. The periphery of the ring member protrudes slightly through the slot 38 to engage the roller or disc 94 with sufficient friction to rotate the roller or disc 84 and the shaft 98 in the bearings I82.

The abrasive is then supplied into the cup or transfer mechanism T through the feed spout 32. The abrasive passing from the feed spout is distributed onto the inner sloping walls I4 and I8 and the abrasive quite quickly attains the velocity of the rotatingcup. The arms 44 intercept the abrasive supplied from the feed spout 32 and.

assist in accelerating the abrasive within the cup. The centrifugal force acting on the abrasive .within the cup urges these particles towards the ring member 58.. During rotation of the cup the r abrasive particles escape through the slot 38 at the point where the ring member 58 is moved or deflected to the open position by the roller or disc 94. Thus, the abrasive escapes through the annular slot 38 in a generally tangential manner with respect to the cup and in the approximate direction indicated by the arrows II8 in Fig. 2. This abrasive is thus discharged from the transfer mechanism at one point in the rotation I8 are angularly shaped as indicated at II8 so that the blades I8 will clear the roller or disc 94,

and this part of the propeller blades I8 may also be beveled for the. purpose of intercepting the abrasive discharged from the transfer mechanism. The housing H and the wear plate or plates I8 are provided with a further opening I I2 as shown in Fig. 4 to permit the assembly and removal of the feed spout holder 84 carrying the disc or roller 94. This opening I I2 may be closed by means of a filler block or plug II4 as shown in Fig. 4, properly maintained in an operative position by any suitable means such as a plurality of clamps H8. i

In operation of the apparatus the rotor R is driven by means of the shaft I4 at a speed willcient for imparting an abrading or blasting velocity to the abrasive particles which will be supplied to the propeller blades I8. Such rotation of the rotor R will also cause the transfer mechanism T or the cup assembly formed of the annular members 34 and .38 to be rotated synchronously therewith. The ring member 58 will also be rotated by reason of the frictional contact thereof with the cup assembly. The centrifugal force developed during such rotation will cause the elastic ring member 58 to more firmly engage the annular seats 58 and 82 adjacent the slot 38 and close this slot at all circumferential tion 88 these particles also leave the cup from both sides of the ring so that two streams or ribbons leave the cup as shown by the arrows I28 in Fig. 1. These streams appear to converge slightly outwardly to overlap each other and provide a dispersion of the abrasive over the width of the propeller blades I8 to prevent channeling thereof, and to provide a more uniform pattern of the particles discharged from the rotor. After one portion of the ring member 58 passes the disc or roller 94 this portion again moves to a position to close the slot 38.

The position of the roller or disc 94 as shown in Figs. 1 and 2 will provide a down blast stream from the periphery of the rotor but it is to be noted that the wheel is universal in application in that the point of discharge from the transfer mechanism T may be readily adjusted by loosening the clamps 88 and rotating the disc member 84 to.arrange the disc or roller 94 at some other -clockdial.position. The disc member 84 may of course be maintained in any adjusted position by tightening the clamps 88.

While the invention has been described with reference to specific structural details shown. in the drawings, and particularly with reference to the constructional features of the transfer mechanism, it is to be understood that changes may be made in these parts of the apparatus without departing from the spirit and scope of the invention as set forth in the appended claims.

What isclaimed is:

1. In abrading apparatus, a rotor including a plurality of propeller blades extending inwardly short of the axis thereof, a cup mounted between the inner ends of said propeller bladesrotating nular slot, a flexible ring member for normally closing said annular slot at all circumferential points of said cup, and means flexing said ring member to open said slot at one Point in the rotation of said cup whereby abrasive may move through the slot to be engaged by said propeller blades at one point in the rotation thereof.

2. In abrading apparatus, a rotor including a plurality of propeller blades extending inwardly short of the axis thereof, a rotatable cup mounted between the inner ends of said propeller blades, said cup having an annular slot therearound, means for feeding abrasive into said cup for movement therefrom through said annular slot, a flexible ring member for normally closing said annular slot at all annular points of said cup, means for deflecting said ring member to a position opening said slot at one point in the rotation of said cup, and means for distributing the abrasive to each side of said ring member whereby the abrasive leaves the cup from both sides of said ring member.

3. In abrading. apparatus, a rotor including a plurality of propeller blades extending inwardly short of the axis of the rotor, a cup mounted between the inner ends of said propeller blades rotating with said rotor, said cup having an annular slot therearound, a flexible ring member for normally closing said annular slot at all annular points of said cup, means for shifting said ring member to a position opening said slot at' one point in the rotation of said cup; means for feeding abrasive into said cup, and an annular partition within said cup distributing the abrasive to each side of said ring member whereby the abrasive leaves the cup from both sides of said ring member.

4. In abrading apparatus, a rotor including a plurality of propeller blades extending inwardly short of the axis thereof, a rotatable cup mounted between the inner ends of said propeller blades, said cup having an annular slot therearound, means for feeding abrasive into said cup for, movement therefrom through said annular slot, an elastic ring member rotating with said cup and subject to the .action of centrifugal force acting thereon for obstructing said slot to the movement of abrasive therethrough at all annu--' lar points thereof, and means for moving said ring member against the action of centrifugal force and to a position unobstructing said slot at one point in the rotation of said cup whereby abrasive may escape from the cup to be engaged by the propeller blades at one point in the rotation thereof.

5. In abrading apparatus, a rotor including a plurality of propeller blades extending inwardly short of the axis thereof, a cup mounted between the inner ends of said propeller blades, rotating with said rotor, said cup having an annular slot therearound, means for feeding abrasive into said cup for movement therefrom through said annular slot, a flexible ring memberrotating with said cup for closing said slot at all annular points thereof and protruding outwardly through said slot at all annular points thereof, and cam means outside the cup engaging and moving the ring member inwardly at one point in the rotation thereof to open said slot at one point in the rotation of the cup for the :discharge of the abrasive.

- B6. In abrading apparatus, a rotor including a plurality of propeller blades extending inwardly short of the axis of the rotor, a rotatable cup mounted between the inner ends of said propeller blades, said cup having 'a peripheral slot therethrough extending circumferentially around the cup, a flexible ring member arranged within said cup for engaging edges of said slotto close the periphery of said cup, means for supplying abrasive into said cup on both sides of said ring member, and a stationary rotatable disc engaging the periphery of said ring member bending the ring member inwardly at the point of engagement with said disc to open said slot at one point in the rotation of said'cup.

7. In abrading apparatus, a rotor including a plurality of propeller blades extending inwardly short of the axis of the rotor, a cup mounted between the inner ends of said propeller blades rotating with said rotor, said cup having a peripheral slot therethrough extending circumferentially around the cup, sloping inner wall surfaces in said cup converging towards said peripheral slot, means for supplying abrasive into said cup whereby the abrasive moves outwardly on said sloping wall surfaces towards said slot, means for closing said slot at all circumferential points of said cup, and means moving said closure means to open said slot at one point in the rotation of said cup.

8. In abrading apparatus, a rotor including a plurality of propeller blades extending inwardly short of the axis of the rotor, a cup mounted between the inner ends of said propeller blades rotating with said rotor, said cup having a peripheral slot therethro'ugh extending circumferentially around \the cup, sloping inner ,wall surfaces in said cupponverging towards said peripheral slot, means for supplying abrasive into said cup whereby the abrasive moves outwardly on said sloping wall surfaces towards said slot, a flexible ring member arranged between and sloping wall surfaces for closing said slot at all circumferential points of said cup, and means for moving said ring member to open said slot at one point in the rotation of said cup.

9. In abrading apparatus, a rotor including a plurality of propeller blades with the inner ends thereof spaced from the axis of the rotor, a hollow annular member mounted between the inner' ends of said propeller blades rotating with the rotor, a second hollow annular member mounted between the inner ends of said propeller blades rotating with the rotor and axially spaced from the first annular member at the periphery thereof, aflexible ring for closing the space between 'said annular members at all circumferential points thereof, means for feeding abrasive into said annular members whereby the abrasive may build up on inner surfaces thereof adjacent said ring, and means for deflecting said ring to open said space at one point in the rotation of said annular members whereby the abrasive may escape between the annular members to be engaged by said propeller blades at one point in the rotation thereof.

at all circumferential parts thereof towards engagement with said valve seats, and a stationary mounted rotatable disc engaging and deflecting said ring member from seated engagement with said annular member as successive parts of the ring member engage said disc.

11. In abrading apparatus, a rotor including a plurality of propeller blades extending inwardly short of the axis of the rotor, a cup mounted between the inner ends of said propeller blades rotating with said rotor, said cup having a peripheral slot therethrough extending circumferentially around the cup, a flexible ring member arranged within said cup for engaging edges of said slot to close the periphery of said cup, means for supplying abrasive into said cup, a rotatable disc engaging said ring member and bending the ring member at the point of engagement with said disc to open said slot at one point in the rotation of said cup, and means for adjusting the position of said disc annularly of said cup.

12. A mechanism for supplying granular particles to a position to be engaged by the propeller blades of a centrifugal blasting rotorat one point in the rotation thereof comprising a hollow annular member arranged at the axis of the rotor, a second hollow annular member spaced from the first annular member at the periphery thereof to provide a circumferentially extending slot between said annular members, means for securing said annular members to said rotor including arms carried by the second annular member extending within the first annular member, an elas tic ring member embracing said arms movable radially outwardly at all circumferential parts thereof to close said slot, means for feeding granular particles into said annular members, and means for moving said ring member radially inward at one point in the rotation of said annular members whereby the granular material may escape through said slot at one point in the rotation of said annular members.

13. A mechanism for supplying granular particles to a position to be engaged by the propeller blades of a centrifugal blastin rotor at one zone in the rotation thereof comprising, a cup arranged at the axis or the rotor, said cup having a peripheral slot therethrough extending circumferentially around the cup, a flexible ring member within said cup for engaging edges of said slot to close the peripher of said cup, means for guiding abrasive into said cup to each side of said ring member, means fo movin said ring member from said slot closing position at one point in the rotation of said cup, and means for maintaining the ring member in a position adjacent said slot.

' WALTER L. KEEFER. 

